Numerous chemical processes utilize acetonitrile as a solvent or wash, resulting in generation of low grade acetonitrile waste streams. When these processes are conducted on a manufacturing scale, the volume of low grade acetonitrile waste stream produced can be substantial. For example, oligonucleotide (DNA and RNA) synthesis is generally conducted via a four step cycle (deblocking, activation/coupling, capping, and oxidation/sulfurization), which is repeated for each nucleotide added until the desired sequence is obtained. Between each step, oligonucleotides bound to a support are washed with acetonitrile to reduce residual reagents from the prior step. This leads to generation of a tremendous volume of acetonitrile waste stream, with on the order of 2,000 metric tons of acetonitrile required to manufacture approximately 1 metric ton of an oligonucleotide-based active pharmaceutical ingredient (API).
Synthetic oligonucleotide sequences are showing promise for therapeutic, diagnostic, and drug target validation applications in the bio-pharmaceutical industry, and the number of oligonucleotide-based drugs currently in pre-clinical or clinical trials is ever increasing. However, oligonucleotide-based API manufacturers are faced with the expense and difficulty of managing this large volume of acetonitrile waste stream. As such, there is an acute need in the industry for methods and systems to reclaim and purify acetonitrile waste streams to generate purified acetonitrile suitable for reuse. Furthermore, other desirable features and characteristics will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and this background.